GE MDS TransNET OEM EL806, Руководство по эксплуатации

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05-3946A01, Rev. C TransNET OEM Integration Guide 13
4.1 Antenna & Feedline Selection
Antennas
The equipment can be used with a number of antennas. The exact style used
depends on the physical size and layout of a system. Contact your factory
representative for specific recommendations on antenna types and hardware
sources.
In general, an omnidirectional antenna ( Figure 9 ) is used at the Master station
site in an MAS system. This provides equal coverage to all of the Remote
sites.
NOTE: Antenna polarization is important. If the wrong polarization is used, a signal reduction
of 20 dB or more will result. Most systems using a gain-type omnidirectional antenna at
the Master station employ vertical polarization of the signal; therefore, the Remote an-
tenna(s) must also be vertically polarized (elements oriented perpendicular to the hori-
zon).


When required, horizontally polarized omnidirectional antennas are also available. Con-
tact your factory representative for details.
At Remote sites and point-to-point systems, a directional Yagi antenna
(
Figure 10 ), is generally recommended to minimize interference to and from
other users. Antennas are available from many sources including GE MDS.
Figure 9.

Omnidirectional Antenna

(mounted to mast)